window.onload(() => {
    const cDiv_stream = document.getElementById('cDiv_stream');
    // const cDiv_video = document.getElementById('cDiv_video');

    // events(cDiv_video)
    events(cDiv_stream)

    function events(dv) {
        let x = 0;
        let y = 0;
        let l = 0;
        let t = 0;
        let isDown = false;
        //鼠标按下事件
        dv.onmousedown = function (e) {
            //获取x坐标和y坐标
            x = e.clientX;
            y = e.clientY;

            //获取左部和顶部的偏移量
            l = dv.offsetLeft;
            t = dv.offsetTop;
            //开关打开
            isDown = true;
            //设置样式  
            dv.style.cursor = 'move';
        }
        //鼠标移动
        dv.onmousemove = function (e) {
            if (isDown == false) {
                return;
            }
            //获取x和y
            var nx = e.clientX;
            var ny = e.clientY;
            //计算移动后的左偏移量和顶部的偏移量
            var nl = nx - (x - l);
            var nt = ny - (y - t);

            dv.style.left = nl + 'px';
            dv.style.top = nt + 'px';
        }
        //鼠标抬起事件
        dv.onmouseup = function () {
            //开关关闭
            isDown = false;
            dv.style.cursor = 'default';
        }
    }
})